THE VALUE OF MOTILE DENSITY, STRICT MORPHOLOGY, AND THE HYPOOSMOTIC SWELLING TEST IN IN-VITRO FERTILIZATION-EMBRYO TRANSFER

This study was conducted to evaluate the effect of a single abnormal s emen parameter on subsequent implantation and pregnancy rates (PRs) fo llowing in vitro fertilization-embryo transfer (IVF-ET). The parameter s evaluated were motile density (MD), strict normal morphology (SNM), and the hypoosmotic swelling (HOS) test. A total of 592 IVF cycles wer e evaluated. Patients were divided into four groups each with one abno rmal semen parameter except for the control: group 1 (n = 509), contro l group: MD greater than or equal to 10 x 10(6)/mL, HOS greater than o r equal to 50%, SNM greater than or equal to 4%; group 2 (n = 51): HOS and SNM normal, MD < 10 x 10(6)/mL; group 3 (n = 14): MD and SNM norm al, HOS < 50%; group 4 (n = 18): MD and HOS normal, SNM < 4%. The impl antation rate was 10.2% for the control group. The implantation rate w as similar for the low MD (9.0%) and the low SNM (16.7%) groups. Howev er, the low HOS group had a significantly lower implantation rate (0%) . The clinical PRs are similar in the control group and low MD and SNM groups, but decreased in the low HOS group (21.5, 15.0, 30.8, and 0%, respectively). Ongoing PRs were also similar with the exception of th e low HOS group (0%). This comparative study supports previous conclus ions that the subnormal HOS test is the best semen parameter available that predicts poor PRs. It also suggests that some qualitative defect in the embryos may result from defective sperm membranes, resulting i n an apparently normal appearance but physiologically defective embryo .